Treatment of tanned or nontanned animal hides



Patented Sept. 26, 1933 1,927,910 PATENT OFFICE TREATMENT OF TANNED OR NONTANNED ANIMAL HIDES Gerhard Balle and Paul Heimke, Frankfort-onthe-Main-Hoechst, Germany, assignor to I. G. Farbenindustrie Aktiengesellschaft, Frankforton-the-Main, Germany No Drawing. Application September 30, 1932. Serial No. 635,705, and in Germany October 7 Claims.

The present invention relates to a treatment of tanned or untanned animal hides.

We have found that for the treatment of animal hides, for instance for the preparation and treatment of leather and furs, there may be used with a particular advantage an aqueous solution of a sulfonic acid compound of the general formula:

wherein X stands for 0,8, O.C0.0, C0.0 NY, CO.NY, O.CO.NY or YN.CO.NY (Y being hydrogen, alkyl or aryl), R stands for a saturated or unsaturated aliphatic radicle containing more than 8 carbon atoms which may be substituted and R1 stands for an aliphatic radicle which may be substituted, or a salt thereof, for instance an alkali metal or ammonium salt.

Such products are, for instance, the following: Palmityl-hydroxyethanesulfonic acid: C16H33- O-CH2-CHz-SO3H, the reaction product obtained from the dodecyl ester of chlorocarbonic acid and hydroxyethane sulfonic acid:

the reaction product obtained from oleic acid chloride and hydroxyethanesulfonic acid:

a-oleyl-hydroxypropane sulfonic acid 01H1-ooH1oHzoH,-s03ri ooorn3o,1

oleyl-methylaminoe thane sulfonic acid:

As additional. tanning agents there may, for in-.

stance, be named: natural tanning agents, such as quebracho and sumac, synthetic tanning agents, such as sulionated condensation products from phenols or naphthalenes with formaldehyde and mineral tanning agents, such as chome extract, chrome alum.

Due to their content of fat-like aliphatic radicles containing long chains, they exert a greasing (stufiing) action on the leather, besides their tanning action and their action in accelerating tanning.

In order to increase the greasing action there may be added to the products greasing agents, suchas train oil, neats-foot oil, mineral oils, or the like. Owing to the good emulsifying properties of the above defined sulfonic acid compounds, it is furthermore possible to produce from water-insoluble oils and fats emulsions which satisfy all requirements of the leather industry as to stability. Such emulsions have the great advantage of penetrating uniformly and readily into the leather.

In contrast to the oil or fat emulsions made by the use of soaps or alkalies, which are also well absorbed by the leather, the emulsions prepared by means of the above defined compounds pos-' sess the great advantage that they are sufiiciently stable towards acids and salts and remove the dyestuffs from the leather to a lesser extent.

Therefore, it is possible to add dyestuffs directly to the liquors containing the sulfonic acid compounds and to effect the dyeing process, which was hitherto carried out separately, together withthe retanning or tanning and greasing. In this method, the topping with basic dyestuffs which is otherwise conducted in a separate bath, may likewise be conducted during the treatment with the sulfonic acid compounds.

The advantage obtained by the use of the greasing baths composed as above indicated, namely, their property of penetrating the goods more uniformly and easily and of being utilized more fully is also obtained in connection with watersoluble oiland fat products. When using the usual soaps as emulsifying agents for oils and fats, the simultaneous use of the above products prevents the formation of precipitates (such as lime soaps) which occurs when hard water is used. The sulfonic acid compounds are even able to redissolve precipitates already formed, so that it is also possible to improve lIlSlllfiCiBIlt greasing effects. When applied in the drumming of dried leather, these products also offer advantages; the leather is treated with these products either before drying or the said compounds are added during the drumming process. The tanning and other treatment of furs by means of the above defined sulfonic acid compounds is carried out in a manner analogous to the treatment of leather.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto, the parts being by weight: I

(1) Sheep pelt pretreated and bated in known manner is pickled in a solution of 1 part of commercial sulfuric acid, 8 parts of sodium chloride and 100 parts of water. Tanning is completed in a known manner in the pickling solution or in a fresh bath by means of the reaction product of the fatty acid chloride of train oil 'and hydroxyethane sulfonic acid. After the tanning is complete, the leather is dried and dressed.

(2) Chrome-tanned calf 4 is dyed with 1 per cent of an acid dyestuff and simultaneously or subsequently treated in the dye bath with 3 per cent of p-cresoxyl- -oleyl-hydroxypropane sulfonic acid; greasing and retanning occur during chromium oxide.

and alkalies and is uniformly absorbed by the leather. There is obtained a plump leather having a fine and soft feel.

(4) Chrome-tanned cow-hide dyed wtih a substantive dyestuff is greased with an emulsion consisting of parts of water, 1 part of soap, 1. I part of the sodium salt of the reaction product of fatty acid chloride of train oil and aminoethanesulfonic acid, 1 part of neats-foot oil and 0.5 part of a mineral oil. The hide may be greased in the dye bath or in a fresh bath. Even if very hard water is used, the formation of lime-soap is prevented and the greasing is in no way detrimentally affected.

(5) Sheep pelt, pickled with 1 part of commercial, hydrochloric acid, 8 parts of sodium chloride and 100 parts of water, is pretreated in a fresh bath with 2 parts of oleyl-hydroxyethanesulfonic acid and then tanned with a solution of chromium sulfate to which sodium carbonate has been added and which contains about 2.5 parts of The leather is fast to boiling already after a short time, no other greasing being required after the tanning.

(6) Sheep pelt which has not been pickled is treated for 4 hours with an emulsion consisting of 150 parts of water, 4 parts of commercial formaldehyde of 40 per cent. strength, 10 parts of the product of condensation of sodium 3- cresoxyl u-oleyl-hydroxypropanesulfonate with formaldehyde. 0.75 part of anhydrous sodium carbonate are then added, and the treatment is contu'nued for a further 2 hours. The leather is then rinsed, after-treated with 2 parts of am-' monium sulfate and dried. The leather thus treated is particularly well suited for making gloves and clothing.

(7) Chrome-tanned cow-hide is greased with an emulsion consisting of 100 parts of water, 1 part of neats-foot oil and 2 parts of a sulfonic acid obtainable by causing phosgene to act upon dodecyl alcohol and causing the dodecyl ester of chlorocarbonic acid thus produced to react with hydroxythane sulfonic acid. The emulsion thus than 8 carbon atoms which may be substituted,

prepared is stable and is uniformly and very readily absorbed by the leather.

(8) If the dodecyl ester of chlorocarbonic acid of example 7 is caused to react with aminoor methylamino ethane sulfonic acid, a urethanelike sulfonic acid is obtained. The emulsion prepared therewith can be used with good success for greasing leather.

(9) By the reaction between oleylamine CisHasNHz and hydroxyethane sulfonic acid in an aqueous solution at an elevated temperature and under pressure there is obtained oleylaminoethane sulfonic acid. If chrome-tanned calf is dyed with 1 per cent of an acid dyestuif and treated simultaneously or subsequently in thesame bath with a solution of 2-3 per cent strength of the aforementioned oleylaminoethane sulfonic acid, the leather is uniformly greased within a short time. After the usual dressing 9. very soft and supple leather is obtained.

The action of the said sulfonic acid may be increased and the solubility particularly in acid baths may be improved, if the sulfonic acid is alkylated in a known manner at the =-NH-- group, for instance, with a methyl, ethyl or a 100 benzyl group.

In the following claims by the term animal hides? there are to be understood both tanned and untanned animal hides.

We claim: 1

1. The process'which comprises treating animal hides with an aqueous solution of a sulfonic acid compound of the general formula:

wherein X stands for 0, S, 0.00.0, 00.0, NY, C0.NY, 0.C0.NY, or YN.C0.NY (Y being hydrogen, alkyl or aryl), R stands for a saturated or unsaturated aliphatic radicle containing more R1 stands for an aliphatic radicle which may be substituted and Z stands for hydrogen, an alkali metal or NH4, while adding a tanning agent.

3. The process which comprises treating animal hides with an aqueous solution of a sulfonic acid compound of the general formula:

Rxmsoiz wherein X stands for 0, S, 0.00.0, 00.0, NY, CONY, 0.CO.NY or YN.C0.NY (Y being hydrogen, alkyl or aryl), R stands for a saturated or unsaturated aliphatic radicle containing more than 8 carbon atoms which maybe substituted, R1 stands for an aliphatic radicle which may be substituted and Z stands forhydrogen, an alkali metal or NHr, while adding a tanningagent and a greasing agent. 1

4. The process which comprises treating animal hides with an aqueous solution of a sulfonic acid compound of the general formula:,

nxmsosz wherein X stands for 00.0 or CO.NY (Y being hydrogen, alkyl or aryl), R stands for an unsaturated aliphatic radicle containing more than 8 carbon atoms which may be substituted, R1 stands for an aliphatic radicle which may be substituted and Z stands for hydroge an alkali metal or NH4.

5. The process which comprises treating animal hides with an aqueous solution of a reaction product of a fatty acid chlorine of train oil and sodium hydromethanesulfonate. 

